Fluid heater for oil well treating apparatus



April 8, 1952 A. c. RUSSELL 2,591,879

FLUID HEATER FOR OIL WELL TREATING APPARATUS Filed April 24, 1950 Zea/n Ouf/ef 30 11%;! illl-lliiiiiiiill .S/eam //7/ef E f 7 d0 45 560/77 rap I N V EN TOR. An aezz/ Cray ,Qussd/ 1, fluiid to be heated.

Patented Apr. 8, 1952 FLUID HEATER FOR OIL WELL TREATING APPARATUS Andrew Craig Russell, Shawnee, Okla. ApplicationApril 24, 1950, Serial No. 157,649

This invention relates to apparatus for use in the heating and treating of viscous liquids which are used in conditioning oil wells, to the end that the pumping efliciency of the well is increased. The primary object of this invention is to provide a relatively simple, inexpensive and easily-operated device capable of applying steam to oil, admixing it therewith, and reheating the mixture whereby a hot material is made available for use as desired. a. a

The most important object of this invention is to provide improved apparatus capable of treating fluids by the application of heat through steam pressure. .5

This is a continuation-in-part of my co-pending application Serial No. 100,280, filed June 20, 1949, for OilWell Treating Apparatus; and an important object is to provide an apparatus having a tank with tube coils disposed therein, oil passing through said coils and being heated by steam contained within the tank and surrounding the coils.

A further object of this invention is to provide a mixing chamber for the steam and oilhaving an elongated, tortuous path which will promote uniform heating and complete mixing of the fluids before they leave the apparatus An important object of this invention is to' provide flexibility in operation of the heater by .,.the special piping'and control arrangement which will make possible alternate paths for the fluid tobe heated, such paths being through the, coils 'orwlthrough the tank external of the coils as -req':uired by the particular characteristics of the ;..A still further object of this invention is to .prdvide heating means for petroleum products, utilizing steam as a part of the means, applied directly to the product under pressure, whereby to inhibit reactions tending to retard free flow ,thereofwithin thetreating apparatus.

Othermore minor objects will be made clear or'become apparent as the following specification progresses, reference being had to the accompanying drawing, wherein:

1 Claim. (01. 257-64) teriorly of the tank l0. A steam supply con- The single figure is a vertical, substantially I z is preferably circular in cross section and pressure-tight. A coil [2 of tube stock and consisting of a plurality of lengths rebent upon themselves is suitably'mounted within the tank I.

An inlet line H connected to a pressurized oil supply (not shown) and having a shut-off valve l6 therein passes through tank [0 adjacentthe top thereof and is joined to one end of the coil l2 within the interior of tank In. A hot oil outlet line 18 passes-through the bottom of tank I0 and is connected to the opposite end of coil 2 for conducting the heated fluid to equipment adapted todirect the same into an oil Well to be treated. h r

A shut-off valve 20 is disposed in the line exnection 22 leading from a suitable supply of steam under pressure, external. of tank [0, enters tank multiple inlets. A steam outlet line 30 connects the uppermost end of tank I0 with the steam ,supply to provide for circulation of the steam and the early removal of air which might become trapped in the tank 10 and exclude introduction of the steam thereinto. The valve 32 operably closes line 30 when required by the operationof the heater.

- A safety valve 34 connectingpthe interior of tank H) with the atmosphere is adjustable toyopen and vent the tank I0v to the atmosphere when the pressure therein exceeds a predetermined,

safe working maximum. When the pressure returns to normal, valve 3'4 closes and confinesthe fluid to the space within tank In. A steamtrap 36 subjacent to tank 10 is connected thereto by conduit 38 which communicates with the bottom.

of tank 10 and has a valve 40 therein to isolate the steam trap 36 from tank ID as required.

Trap 36 insures that any accumulation of steam condensate in the bottom of tank It! will 3 be drained off, thereby maintaining the tube coils I2 completely surrounded by steam at all times. An interconnecting line 42 is joined to oil inlet I4 and enters tank I0. A shut-off valve 44 in line 42 allows the selection of this flow path as required by the operation of the system.

A second interconnecting line 46 is disposed between coil outlet line I8 and tank outlet line 38, thereby placing coil I2 in communication with trap 36, when required by the introduction of steam in coil I2 and as selected by opening shut-ofi valve 46. A third interconnecting line 50 is joined to oil outlet line I8, and the bottom of tank I0. A valve 52 controls the flow of the contents of tank I6 into line I8.

In operation, oil to be processed is supplied to the heater through line I4 from an oil storage, the contents of line I4 being pressurized and circulated by a suitable pump. Said storage and pump not being a part of this invention are not shown in the drawing. With valves I6 and 24 open, oil enters coil I2, and steam is mixed therewith by virtue of the steam connection to coil I2 from line 22 which extends from a source of steam at a higher pressure than that found in coil I2.

' The mixture of oil and steam flows through coil I2, the steam giving up heat to the oil and condensin as it moves along. Steam from the above-mentioned source is, also, conducted into tank I0 through lines 26 which communicate with the interior of tank I0 when valves 28 are 'jopened. The steam fills the space around coil I2 and serves to reheat the mixture inside the coil as it passes therethrough. Steam and air may return to the boiler as required through steam outlet line 30 connected to the uppermost portion of tank II) when valve 32 is opened.

' After the mixture passes through coil I2 and has been heated to a temperature approximately that of the steam surrounding the coil I2, line I8 connected to the coil I2 interiorly of the tank I0 conducts the hot mixture to an oil well or other point of usage as desired through the use of :suitable equipment forming no part of this invention.

During the reheating of the fluid in the coil I2, condensation of steam will occur and gravitate to the bottom of tank I0. Steam trap 36 has been provided to allow the passage of water from the tank ID to a receptacle from which it may be' returned to the boiler. The trap 36, however, will not allow steam to escape from tank II]. The connecting line 38 from the lowermost part of tank I0 to the trap 36 has been disposed in such a manner that'condensate will flow by gravity into the trap 36 and be discharged as it accumulates.

' It is possible with the pipin and valve arrangement provided to change the relative disposition of the oil and the steam in the heater structure. By closing the valve I6 in the normal inlet and opening valve 44 in line 42, oil flow will be diverted from the coil I2 into the tank I0, thereby filling the tank I0 with oil in surrounding relationship to coil I2. To keep the flow path, 'it is necessary to open valve 52 in line 50 at the bottom of tank I6 and thereby connect the tank I 0 to outlet line I8.

With valve 24 in line 22 open, steam will be admitted to the coil and thereby heat the oil in the tank as the steam condenses. To disposeof the condensate which will accumulate in coil I2, it is required to connect the coil to steam trap 36, trap 36 having been previously isolated '4 from tank I0 by closing valve 46 in line 38. The opening of the valve 48 in line 46 will place coil I2 in communication with line 38 and steam trap 36.

It will be noted that valve 26 disposed between line 46 and line 50 will be closed to prevent the flow of oil into the steam trap 36. Steam may be introduced into the oil content of tank III by opening either or both of the valves 28 in lines 26. Valve 32 in line 30 may be used to prevent the flow of oil from tank I0 into the steam boiler if the oil pressure is higher than the steam supply pressure. Valve 32, therefore, would ordinarily be closed when oil is being introduced to the tank.

The introduction of steam into the oil as it enters the heating coil I2 is instrumental in increasing the efliciency of the heater and raising the outlet temperature of the oil to a maximum. As the steam enters the oil stream, violent turbulence results and its viscosity is immediately reduced. Both of these efiects are beneficial to the transfer of the heat to the fluid because the thickness of the boundary layer at the tube wall is thereby reduced. Consequently, the overall heat-transfer co-eflicient is increased, the result bein absorption of the required heat in small, inexpensive equipment. It is obvious that the smaller equipment is more economical, not only as to initial cost of construction but required space in use and convenience of operation.

A further advantage of this novel device is the small volume of oil contained in the coil which makes for practically instantaneous results upon starting up. If such operation is desired, the oil to be heated would be introduced to the coil, and it would, therefore, be unnecessary to heat up a large volume of oil in the tank before the hot oil is obtained. Further, heavy tank construction would not be required if it is necessary to operate at high oil pressures. The wall thickness required by the tube coil I2 for high pressures would be small relative to that required for a tank designed to operate at the same pressures, thus presenting an overall economical structure.

The coil pattern as provided will allow freedom of movement that results from thermo-expansion and construction as variation of temperatures throughout the heater occur. Therefore, expansion joints are not required to accommodate the changes in length of the tube as it heats because of the inherent flexibility of the return bends.

The introduction of oil to tank I!) rather than coil I2 allows the storage of large quantities of heated oil, where such is required to furnish large flows for short period-s. Therefore, the flexibility that is inherent in being able to change the oil from the coil to the interior of the tank surrounding the coil is of advantage to the extent of reducing the size of equipment required inlet pipes, a valved steam outlet pipe and valved outlet means communicating with said tank; a continuous, tubular coil in the tank and having a valved inlet end extending through the tank adjacent the top thereof and a valved outlet end extending through the bottom of said tank; means for directing oil to be treated to said oil inlet pipe and to said inlet end of the coil; 9. valved steam inlet tube connected with said coil adjacent its inlet end; a steam trap; a valved conduit joining the tank at said bottom thereof with said steam trap; and a valved tubular member joining the coil adjacent its outlet end with said conduit.

ANDREW CRAIG RUSSELL.

6 REFERENCES omen The following references are of record in the file of this patent:

UNITED STATES PATENTS 

